Echogenic occlusive balloon and delivery system

ABSTRACT

A vessel occlusion apparatus includes an elongate shaft having a fluid delivery lumen; and an expandable member carried on a distal end portion of the shaft, the expandable member comprising a body defining an interior region, the interior region in communication with the fluid delivery lumen, the body comprising a wall having one or more embedded fluid pockets therein, each of the one or more pockets containing a fluid capable of being imaged, e.g., having echogenic qualities for detection using ultrasound imaging.

FIELD OF INVENTION

The field of the application relates to medical devices, and moreparticularly, to an echogenic occlusive balloon and delivery system foruse in performing medical procedures, such as liver resection.

BACKGROUND

Many liver resection procedures are performed every year. For example, aliver may need to be resected to remove a tumor, a cancerous cell, or adiseased part of a liver. Liver resection surgery is a risky procedurebecause after the liver is resected, the remaining liver may bleedsignificantly due to the vascularity nature of the liver. In some cases,a patient may even die from significant bleeding after a liver resectionprocedure.

In many medical procedures, balloons have been used to occlude bloodvessels and aneurysms. However, balloons have not been used to occludevessels within a liver during a liver resection procedure. This isbecause delivering a balloon within a target vessel inside an organ isdifficult. In order to accurately position a balloon inside a patient,the balloon would need to be visualized using an imaging device such asan ultrasound imager. However, existing balloons are not made from amaterial that allows them to be clearly visualized using ultrasound.Sometimes, after the balloon is inflated with liquid, the balloonremains very difficult to be imaged with ultrasound. This is becauseliquid within the balloon is not echogenic, thereby preventing a clearultrasound image of the balloon from being obtained.

Sometimes, in order to aid a physician to visualize the balloon afterthe balloon has been placed in a patient's body, the balloon can includea radio-opaque marker secured thereto. The radio-opaque marker is thenimaged using an imaging device located outside the patient's body.However, adding the radio-opaque marker to the balloon increases amanufacturing cost of the balloon. In addition, there is a risk that theradio-opaque marker may become detached from the balloon while theballoon inside the patient's body.

Other medical devices also use radio-opaque markers to assist aphysician in positioning and/or confirming a position of the devices.For example, the catheter used to deliver the balloon may also include aradio-opaque marker secured to a distal end of the catheter. During use,the radio-opaque marker at the catheter can be imaged using an imagingdevice, thereby allowing a physician to steer the catheter distal end totarget area within a patient's body. However, the use of theradio-opaque markers in these device increases the manufacturing cost ofthese devices, and there is a risk that a marker may become detachedfrom a device while the device is inside the patient's body.

SUMMARY

In accordance with one embodiment, a vessel occlusion apparatus includesan elongate shaft with an expandable member carried on a distal endportion of the shaft, the expandable member comprising a body definingan interior region, the interior region in communication with the fluiddelivery lumen, the body comprising a wall having one or more embeddedfluid pockets therein.

In accordance with another embodiment, an elongate tubular deliverymember is provided, the tubular member having a proximal portion, adistal portion, a lumen extending between the proximal and distalportions, and a wall defining at least a portion of the distal portionof the tubular member, the wall having one or more embedded fluidpockets therein.

In accordance with yet another embodiment, a vessel occlusion systemincludes, in combination, an echogenic occlusive balloon apparatus andan echogenic delivery apparatus. The balloon apparatus comprises anelongate shaft having a fluid delivery lumen, and an expandable ballooncarried on a distal end portion of the shaft, the balloon comprising aballoon body defining an interior region in communication with the fluiddelivery lumen, the balloon body comprising a wall having one or moreembedded fluid pockets therein. The delivery lumen comprises an elongatetubular delivery member having a proximal portion, a distal portion, alumen extending between the proximal and distal portions and sized toaccommodate insertion of the balloon apparatus there through, and a walldefining at least a portion of the distal portion of the tubulardelivery member, the tubular member wall having one or more embeddedfluid pockets.

Other and further aspects and features of the embodiments will beevident from reading the following description of the embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate the design and utility of embodiments of theapplication, in which similar elements are referred to by commonreference numerals. In order to better appreciate how advantages andobjects of various embodiments are obtained, a more particulardescription of the embodiments are illustrated in the accompanyingdrawings. Understanding that these drawings depict only typicalembodiments of the application and are not therefore to be consideredlimiting its scope, the embodiments will be described and explained withadditional specificity and detail through the use of the accompanyingdrawings.

FIG. 1 illustrates an vessel occlusion system in accordance with someembodiments, showing the vessel occlusion system having a balloonconfined within a tubular member;

FIG. 2 illustrates the vessel occlusion system of FIG. 1, showing theballoon deployed out of a lumen of the tubular member;

FIG. 3 is a sectional view of a wall of the balloon of FIG. 1 inaccordance with some embodiments;

FIG. 4 is a sectional view of a wall of the balloon of FIG. 1 inaccordance with other embodiments;

FIG. 5 is a sectional view of a wall of the tubular member of FIG. 1 inaccordance with some embodiments;

FIG. 6 is a sectional view of a wall of the tubular member of FIG. 1 inaccordance with other embodiments;

FIGS. 7A-7D illustrates a method of occluding a vessel using the vesselocclusion system of FIG. 1 in accordance with some embodiments.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1 illustrates a vessel occlusion system 10 in accordance with someembodiments. The vessel occlusion system 10 includes a tubular member12, a shaft 14, and a balloon 16.

The tubular member 12 has a proximal end 20, a distal end, 22, and alumen 24 extending between the proximal and distal ends 20, 22. In theillustrated embodiments, the distal end 22 has a sharp distal tip 23 forpuncturing tissue. In other embodiments, the distal end 22 has a blunttip. The tubular member 12 can be made from a variety of materials, suchas a polymer, a metal, or an alloy. In the illustrated embodiments, thetubular member 12 has a rigid construction, which prevents the tubularmember 12 from being bent. In other embodiments, the tubular member 12has a flexible construction, which allows the tubular member 12 to bebent during use. For example, the tubular member 12 can be made from amalleable material that allows the tubular member to be bent to adesired shape by a physician. In another example, the tubular member 12is in a form of a catheter body, which allows the tubular member to besteered through a vessel during use.

The shaft 14 is disposed at least partially within the tubular memberlumen 24, and has a proximal end 26, a distal end 28, and a lumen 30extending between the proximal and distal ends 26, 28. The shaft 14 canbe made from a variety of materials, such as a polymer, a metal, or analloy. In the illustrated embodiments, the shaft 14 has a flexibleconstruction, which allows the shaft 14 to be bent during use.Alternatively, the shaft 14 can have a rigid construction. The system 10further includes a handle 40 secured to the shaft proximal end 26, whichallows a physician to manipulate the shaft 14. Alternatively, the handle40 is optional, and the system 10 does not include the handle 40. In theillustrated embodiments, the system 10 also includes a fluid source 50,which is coupled to the proximal end 26, and is in fluid communicationwith the shaft lumen 30. During use, the fluid source 50 delivers fluid,such as saline, to the balloon 16 to thereby inflate the balloon 16.

The balloon 16 is secured to the distal end 28 of the shaft 14. When theballoon 16 is not inflated, it has a deflated configuration, whichallows it to be housed within the tubular member lumen 24. The balloon16 can be deployed from the distal end 22 by advancing the shaft 14distally relative to the tubular member 12, and can be inflated toassume an expanded configuration (FIG. 2).

FIG. 3 illustrates a cross sectional view of a wall 100 of the balloon16. The balloon wall 100 includes a plurality of fluid pockets 102,which allows the balloon wall 100 to be imaged by ultrasound during use.As used in this specification, the term “fluid pocket” refers to apocket of gas, which may or may not be air, or a pocket of liquid. Inthe illustrated embodiments, the fluid pockets 102 are distributedaround the entire wall 100 that forms the balloon 12. Alternatively, thefluid pockets 102 are only located within a part of the wall 100 thatforms the distal portion of the balloon 12. Also, in the illustratedembodiments, the volume of the fluid pockets 102 within a unit length ofthe wall 100 is at least 10%, and more preferably, more than 50% of thevolume of the wall in the unit length. Having such volume quantity ofthe fluid pockets allows a substantial cross section of the balloon wall100 to be imaged using ultrasound. In other embodiments, the volume ofthe fluid pockets 102 within a unit length of the wall 100 can be otherpercentage values of the volume of the wall in the unit length.

It should be noted that the configuration of the fluid pockets 102 isnot limited to the example shown in the figure, and that the fluidpockets 102 can have other configurations in other embodiments. Forexample, instead of having a circular shape, each of the fluid pockets102 can have an elongated shape that extends a distance along a lengthof at least a portion of the balloon wall 100 (FIG. 4). Suchconfiguration allows a continuous portion of the balloon wall 100 to beimaged using ultrasound energy. In some embodiments, the elongated fluidpockets 102 can be created by securing a first sheet 110 of material toa second sheet 112 of material using an adhesive 114 at selectedlocations. Other techniques known in the art of balloon making can alsobe used. In other embodiments, instead of elongated fluid pockets 102,the balloon 16 can have fluid pockets 102 having other shapes, such asan irregular shape.

The balloon 16 can be made using a variety of procedures. In someembodiments, the balloon 16 can be made using a mandrel moldingtechnique. In such cases, a mandrel, the external shape and size ofwhich mimics the desired shape and size, in its expanded mode, of theballoon to be created, is dipped one or more times into a solution ofthe substance from which the balloon body is to be formed until adesired wall thickness is achieved. The balloon body is allowed to dryon the mandrel and is then removed. The solution can be any materialknown in the art of balloon making. Before the mandrel is dipped intothe solution, gas can be introduced into the solution. For example, thesolution can be stirred or agitated to thereby introduce air into thesolution. Alternatively, one or more tubes can be inserted into thesolution to blow air into the solution. Because the solution has aplurality of fluid pockets, the formed balloon body will have aplurality of fluid pockets, as described in embodiments herein.

In other embodiments, the balloon 16 can be formed using expansion orblow molding. Here, a precursor body made of a desired substance, e.g.,a piece of polyester tubing, is placed into a mold, the inner dimensionsof which, like the external dimensions of the mandrel, are the desiredsize and shape of the expanded mode balloon body to be formed. Theprecursor body includes fluid pockets. One end of the tube is closed offand a fluid, such as a pressurized gas, is introduced through the openend of the tube, causing it to inflate. The mold is heated or,alternatively, it is ported to permit introduction of a heated fluid. Ineither case, when the tube comes in contact with the interior surface ofthe mold or when it contacts the heated fluid it, too, is heated andthereupon softened such that, when brought into contact with the innersurface of the mold, it conforms to its dimensions. The system is thencooled to permanently set the expanded size and shape of the balloonbody to that of the mold. Because the precursor body has a plurality offluid pockets, the formed balloon body will have a plurality of fluidpockets, as described in embodiments herein.

In other embodiments, instead of, or in addition to, the balloon 12having fluid pockets 102, one or both of the tubular member 12 and theshaft 14 can also include a plurality of fluid pockets, which allows thetubular member 12 and/or the shaft 14 to be imaged by acoustic energyduring use. For example, in some embodiments, the wall 200 of thetubular member 12 can include a plurality of fluid pockets 202 (FIG. 5).In the illustrated embodiments, the fluid pockets 202 are located alonga substantial portion (e.g., more than 50%) of a length of the tubularmember 12, thereby allowing a substantial portion of the length of thetubular member 12 to be imaged by ultrasound energy. In otherembodiments, the fluid pockets 202 are located at the distal end 22 ofthe tubular member 12, which allows the distal end 22 of the tubularmember 12 to be imaged. If the distal end 22 has the sharp distal tip23, the fluid pockets 202 allow the distal tip 23 to be imaged usingultrasound. It should be noted that the configuration of the fluidpockets 202 is not limited to the example shown in the figure, and thatthe fluid pockets 202 can have other configurations in otherembodiments. For example, instead of having a circular shape, each ofthe fluid pockets 202 can have a rectangular shape (FIG. 6), or any ofother shapes.

In the illustrated embodiments, the volume of the fluid pockets 202within a unit length of the wall 200 is at least 10%, and morepreferably, more than 50% of the volume of the wall in the unit length.Having such volume quantity of the fluid pockets allows a substantialcross section of the tubular member wall 200 to be imaged usingultrasound. In other embodiments, the volume of the fluid pockets 202within a unit length of the wall 200 can be other percentage values ofthe volume of the wall in the unit length.

Various techniques can be used to form the tubular member 12 having aplurality of fluid pockets. In some embodiments, the tubular member 12can be extruded from a material having a plurality of fluid pockets. Inother embodiments, the tubular member 12 can be formed from a sheet ofmaterial having a plurality of fluid pockets. In such cases, the sheetcan be rolled into a tubular shape to form the tubular member 12. Infurther embodiments, two tubular structures can be positioned coaxiallyrelative to each other, and are secured to each other at certainlocations. In such cases, the outer tubular structure forms the exteriorsurface of the tubular member 12, and the inner tubular structure formsthe interior surface of the tubular member 12, with the spacing betweenthe outer and inner tubular structures being the fluid pocket(s) 202.

In any of the embodiments of the system 10 described herein, the system10 can further include a steering mechanism for steering the shaftdistal end 28. For example, in some embodiments, the system 10 canfurther include one or more steering wires (not shown) secured to thedistal end 28. The steering wire(s) can be housed within the shaft lumen30, or within a wall of the shaft 14. During use, the steering wire canbe pulled from a distal end (e.g., using a knob at the handle 40), tothereby steer the shaft distal end 28.

It should be noted that the system 10 is not necessarily limited to theconfigurations described previously, and that the system 10 can haveother configurations in other embodiments. For example, in otherembodiments, the balloon 16 can have different shapes and/or sizes. Infurther embodiments, instead of the balloon 16, the system 10 caninclude another expandable member. For example, the system 10 caninclude an expandable cage (not shown) secured to the distal end 28 ofthe shaft 14, and a sheet of material covering the cage. The sheet ofmaterial may include one or more fluid pockets, which allows the sheetto be imaged by ultrasound during use. The cage has a collapsedconfiguration when housed within the lumen 24 of the tubular member 12,and expands to form an expanded configuration when outside the lumen 24.In other embodiments, the system 10 does not include the tubular member12. Instead, the balloon 16 and the shaft 14 can be used with otherdevices, such as an introducer sheath.

FIGS. 7A-7D illustrate a method of treating tissue using the treatmentsystem 10 of FIG. 1 in accordance with some embodiments. The method willbe described with reference to treating liver tissue. However, in otherembodiments, the method can be similarly performed to treat tissue atother parts of a body.

First, an incision is made to create an opening 700 at a patient's skin702, and the tubular member 12 is inserted through the opening 700 toreach a liver 704 (FIG. 7A). In the illustrated embodiments, the distalend 22 of the tubular member 12 has the sharp tip 23, and therefore, canbe used to puncture the liver 704. The tubular member 12 is thenadvanced until the distal tip 23 puncture a target vessel 706 in theliver 704, thereby creating a punctured opening 710 at the vessel wall.As shown in FIG. 7A, only one side of the vessel 706 is punctured. Inthe illustrated embodiments, the tubular member 12 is rigid, whichprevents the tubular member 12 from bending as the tubular member 12 isinserted at least partially through the liver 704. This in turn, allowsthe distal end 22 of the tubular member 12 to be positioned accuratelywithin the liver 704. In other embodiments, if the tubular member 12 isflexible, it can be inserted into a vessel that leads to a target site,such as a heart.

In some embodiments, the distal end 22 of the wall of the tubular member12 includes a plurality of fluid pockets 202, such as gas, which allowsthe distal end 22 to be imaged by an ultrasound imaging device while thedistal end 22 is being positioned. In other embodiments, the fluidpockets 202 include a radio-opaque liquid (e.g., liquid havingradio-opaque particles), which allows the distal end 22 to be imagedusing other imaging technique. In further embodiments, the wall of thetubular member 12 does not include the plurality of fluid pockets 202.In such cases, the tubular member 12 can include a radio-opaque marker(e.g., in a form of a ring) that is secured to the distal end 22. Theradio-opaque marker can be imaged by a fluoroscope or a x-ray device,which allows a physician to determine the position of the distal end 22within the liver 704.

In the illustrated embodiments, before the balloon 16 is deployed at thetarget site, the balloon 16 is housed within the lumen 24 of the tubularmember 12, and has a deflated configuration. After the distal end 22 ispositioned at a desired position, the shaft 14 is advanced distallyrelative to the tubular member 12 to thereby push the balloon 16 out ofthe distal end 22 (FIG. 7B). As shown in the figure, the taperedconfiguration of the distal end 22 biases the balloon 16 to move towardsone direction (e.g., upstream, which is the left side in the example)within the vessel 706, as the balloon 16 exits from the distal end 22.Alternatively, the tubular member 12 can be rotated such that the distalopening at the distal end 22 points towards another direction (e.g., adownstream direction). In some embodiments, the distal end 28 of theshaft 14 is steerable. In such cases, the distal end 28 of the shaft 14can be steered to position the balloon 16 after the balloon 16 exitsfrom the distal end 22. In other embodiments, the distal end 28 of theshaft 14 has a pre-bent configuration. In such cases, after the balloon16 exits from the distal end 22 of the tubular member 12, the bentdistal end 28 of the shaft 14 will automatically turn the balloon 16towards the direction of the bent.

In other embodiments, the distal end 22 does not have the sharp tip 23.In such cases, a needle (not shown) can be inserted within the lumen 24of the tubular member 12 and exits from the distal end 22. The needle isthen used to pierce into the liver tissue. The needle and the tubularmember 12 are advanced distally together until the needle punctures thevessel 706 to create the opening 710. The distal end 22 of the tubularmember 12 is then further advanced into the opening 710 until the distalend 22 is located within the vessel 706. Next, the balloon 16 and theshaft 14 are inserted into the lumen 24 of the tubular member 12, andthe shaft 14 is advanced distally relative to the introducer until theballoon 16 is deployed out of the lumen 24 of the tubular member 12.

In other embodiments, the system 10 does not include the tubular member12. In such cases, an introducer (not shown) with a sharp tip can beused. The introducer is inserted through the opening 700 and is used topuncture the liver 704. The introducer is then advanced until its distaltip punctures the target vessel 706, as similarly discussed. Theintroducer may have a rigid construction, which prevents bending of theintroducer as it is inserted into the liver 704, and allows theintroducer to be accurately positioned within the liver 704. In someembodiments, a wall of the introducer may include a plurality of fluidpockets, which allows the introducer to be imaged by ultrasound. Inother embodiments, the introducer may include a radio-opaque markersecured to its distal end, which allows the introducer to be imaged by afluoroscope or a x-ray device. Next, the balloon 16 and the shaft 14 areinserted into the lumen of the introducer, and the shaft 14 is advanceddistally relative to the introducer until the balloon 16 is deployed outof the lumen of the introducer.

Next, inflation fluid, which can be gas or liquid, is delivered to theballoon 16 to inflate the balloon 16 (FIG. 7C). The balloon 16 isexpanded until it substantially occludes the vessel 706, therebypreventing, or substantially reducing, flow of blood downstream. In theillustrated embodiments, before the balloon 16 is expanded, it ispositioned away from the punctured opening 710 at the vessel 706. Suchtechnique reduces the risk of rupturing the vessel 706 through thepunctured opening 710 by the balloon 16 as it is inflated, which couldoccur if the balloon 16 is placed closely next to the punctured opening710 at the vessel 706. In some embodiments, the balloon 16 includes thefluid pockets 102. The fluid pockets 102 may include gas, which allowsthe balloon 16 to be imaged by ultrasound, so that a physician canvisualize the position of the balloon 16 as the balloon 16 is beingpositioned through the tubular member 12 and within the vessel 706.Alternatively, the fluid pockets 102 may include a radio-opaque liquid,which allows the balloon 16 to be imaged by other imaging techniques.

After the vessel 706 has been desirably occluded, the liver 704 is thenresected (FIG. 7D). Such can be accomplished by using a surgical knife,an ablation device, or other cutting devices. As shown in theembodiments, because the vessel 706 is substantially occluded by theballoon 16, after the liver 704 has been resected, the amount ofbleeding from the vessel 706 is prevented or substantially reduced.Although only one balloon 16 is used in the illustrated embodiments, inother embodiments, more than one balloons 16 can be used to occlude morethan one vessel in the liver 704.

After bleeding has been prevented, the balloon 16 is then deflated andremoved from the vessel 706.

In the above embodiments, the balloon 16 has been described as anocclusion device for occluding a vessel. In other embodiments, insteadof a vessel, the balloon 16 can be sized to occlude other locations,such as an aneurysm, temporary vascular occlusion, within a patient'sbody. In further embodiments, instead of a liver, the balloon 16 can beused as an occlusion device in other parts of a patient's body, such asa heart, or a bronchi.

Also, in other embodiments, the balloon 16 can function as a dilator.For example, the balloon 16 can be delivered underneath a patient'sskin, and is inflated to dilate a portion of the skin. In furtherembodiments, the balloon 16 can be used in a variety of medicalprocedures such as angioplasty where it is used to dilate a bloodvessel.

In other embodiments, the balloon 16 functions as an anchor. Forexample, the balloon 16 can be delivered within a vessel, and isinflated to bear against a surface of the vessel to thereby secureitself against the vessel. In such cases, a medical device coupled tothe balloon 16 is then anchored to the vessel.

In further embodiments, the balloon 16 functions as an ablation device.For example, the balloon 16 can be used in ablation procedures wherethey are used to deliver energy to tissue, such as heart tissue. In suchcase, the balloon 16 is typically carried at or adjacent a distal end ofa catheter which, with the balloon 16 in a deflated configuration, isinserted into a patient's body, wherein the balloon 16 is inflated whenit reaches a target site. Energy is then delivered to an electrodelocated in, or on the surface of, the balloon, which is transmitted tothe target tissue. In some embodiments, the balloon 16 includes metallicdusts or metallic elements (e.g., made from foil) disposed on itssurface, thereby forming one or more conductive regions on the balloonsurface. Each conductive region functions as an electrode, and issecured to an electrode wire, which delivers electrical energy from agenerator to the electrode.

In other embodiments, cold fluid can be delivered into the balloon 16,and the balloon 16 can then be used to remove energy from tissue tothereby injure the tissue.

Although the above embodiments of the system 10 have been described ashaving the balloon 16, in other embodiments, the system 10 may notinclude the balloon 16 and/or the shaft 14. For example, in furtherembodiments, the system 10 includes the tubular member 12, and not theballoon 16 and the shaft 14. In such cases, the tubular member 12 can beused to house or deliver other medical devices, such as an imagingdevice, an occlusive device, an anchoring device, a cutting device, anablation device, or a biopsy device. At least a portion, e.g., thedistal end 22, of the tubular member 12 includes the fluid pockets 202,which allows the portion to be imaged by ultrasound. The distal end 22may have the sharp distal tip 23, or alternatively, a blunt tip. In someembodiments, the tubular member 12 has a rigid construction, whichprevents the tubular member 12 from being bent during use. In otherembodiments, the tubular member 12 is flexible. For example, the tubularmember 12 can be a catheter, a micro-catheter, or a sheath.

Thus, although several embodiments have been shown and described, itwould be apparent to those skilled in the art that many changes andmodifications may be made thereunto without the departing from the scopeof the invention, which is defined by the following claims and theirequivalents.

1. A vessel occlusion apparatus, comprising: an elongate shaft having afluid delivery lumen; and an expandable member carried on a distal endportion of the shaft, the expandable member comprising a body definingan interior region, the interior region in communication with the fluiddelivery lumen, the body comprising a wall having one or more embeddedfluid pockets therein.
 2. The apparatus of claim 1, wherein theexpandable member comprises an inflatable balloon.
 3. The apparatus ofclaim 1, each of the one or more fluid pockets containing a fluid thatcan be imaged using an imaging device.
 4. The apparatus of claim 3, thefluid comprising a gas.
 5. The apparatus of claim 3, the fluidcomprising a liquid.
 6. The apparatus of claim 3, the imaging devicecomprising a fluoroscopic imager.
 7. The apparatus of claim 3, theimaging device comprising an ultrasound imager.
 8. The apparatus ofclaim 1, wherein the one or more fluid pockets have elongate shapes. 9.The apparatus of claim 1, the wall comprising a plurality of embeddedfluid pockets.
 10. The apparatus of claim 1, wherein the expandablemember is sized to occlude a blood vessel.
 11. The apparatus of claim 1,wherein at least a portion of the wall of the expandable member body iselectrically conductive.
 12. An apparatus for use in a medicalprocedure, comprising: an elongate tubular delivery member having aproximal portion, a distal portion, a lumen extending between theproximal and distal portions, and a wall defining at least a portion ofthe distal portion of the tubular member, the wall having one or moreembedded fluid pockets therein.
 13. The apparatus of claim 12, whereinthe distal portion comprises a tissue-piercing distal tip.
 14. Theapparatus of claim 12, further comprising a needle sized to be carriedin the lumen, such that a distal tip of the needle protrudes from adistal opening of the elongate tubular member.
 15. The apparatus ofclaim 12, each of the one or more fluid pockets containing a fluid thatcan be imaged using an imaging device.
 16. The apparatus of claim 15,the fluid comprising a gas.
 17. The apparatus of claim 15, the fluidcomprising a liquid.
 18. The apparatus of claim 15, the imaging devicecomprising a fluoroscopic imager.
 19. The apparatus of claim 15, theimaging device comprising an ultrasound imager.
 20. The apparatus ofclaim 12, wherein the one or more fluid pockets have elongate shapes.21. The apparatus of claim 12, the wall comprising a plurality ofembedded fluid pockets.
 22. The apparatus of claim 12, wherein at leastone fluid pocket extends along a substantial portion of a length of thetubular member.
 23. A vessel occlusion system, comprising: incombination, an echogenic occlusive balloon apparatus and an echogenicdelivery apparatus, wherein the balloon apparatus comprises an elongateshaft having a fluid delivery lumen, and an expandable balloon carriedon a distal end portion of the shaft, the balloon comprising a balloonbody defining an interior region in communication with the fluiddelivery lumen, the balloon body comprising a wall having one or moreembedded fluid pockets therein; and the delivery lumen comprises anelongate tubular delivery member having a proximal portion, a distalportion, a lumen extending between the proximal and distal portions andsized to accommodate insertion of the balloon apparatus there through,and a wall defining at least a portion of the distal portion of thetubular delivery member, the tubular member wall having one or moreembedded fluid pockets.
 24. The system of claim 23, each of therespective fluid pockets in the balloon body wall and tubular deliverymember wall containing an echogenic fluid that can be imaged using anultrasound imaging device.
 25. The system of claim 24, the fluidcomprising a gas.
 26. The system of claim 24, the fluid comprising aliquid.
 27. The system of claim 23, each of the respective fluid pocketsin the balloon body wall and tubular delivery member wall havingelongate shapes.
 28. The system of claim 23, wherein the balloon issized to occlude a blood vessel.
 29. The system of claim 23, wherein atleast a portion of the balloon body wall is electrically conductive.